When approached with the idea of coming up with a list of the 10 most influential works of the past 1,000 years, I thought, "This will be fun!" Beloved, familiar images - the Mona Lisa, a still life by Czanne - flowed across my mind. As I sat down to write, however, the task seemed more daunting. Where in such a "Top 10" list, for instance, would fall African tribal sculpture, Indian miniatures, Amish quilts, and the sublime raked-sand gardens of Kyoto, Japan? I approached my list, finally, based on personal encounters with works that have inspired me, as well as many of the living artists with whom I have worked. Artists do not see the art of the past as frozen in time, but as a kind of living library of ideas, solutions, and inspiration. They look at works that offer insights about ways to convey space, color, light, and movement, or that redefine the nature of art itself.

1. Giotto - Arena Chapel frescoes (1305-06). Three narratives depicting the life of the Virgin, the life of Christ, and the Passion, Crucifixion, and Resurrection span the walls of Arena Chapel in Padua, Italy. The figures are remarkable for their humanity, not only as real bodies having bulk and weight, but for their extraordinary psychological connections to one another. Expressive, "knowing" glances between figures are zones of silent communication detached from the cacophony of events taking place.

2. Jan Vermeer - Woman Holding a Balance (1664), oil on canvas. Vermeer takes a simple, everyday act and through the use of light and composition transforms it into a sanctified moment of private reflection. The light flooding through the window permeates the scene and infuses it with a sense of the mystery present in the familiar.

3. Eadweard Muybridge - Head-spring, a Flying Pigeon Interfering (1885). Muybridge's photographic studies of motion broke down the stages of movement to reveal the components of a single action. Using the camera to demonstrate what the eye could not see, Muybridge contributed significantly to the ability of both artists and scientists to understand and portray the world around them.

4. Marcel Duchamp - Fountain (1917), Porcelain urinal, 23-5/8 in. tall. Duchamp changed the definition of art when he turned a detached urinal on its side, signed it with the pseudonym R. Mott, and submitted it to the exhibition of the Society of Independent Artists. By removing an everyday object from its normal context and calling it art, Duchamp empowered the artist to determine the definition of art.

5. Kazimir Malevich - White on White (1918), oil on canvas. Malevich was the first artist to use pure geometric abstraction as the subject of his work. "White on White" abandons any reference to the outside world in favor of the artist's depiction of pure feeling. Malevich intended this type of expression as a kind of universal language, accessible and familiar to all people.

6. Georgia O'Keeffe - The Lawrence Tree (1929), oil on canvas. O'Keeffe opened our eyes to the natural world in a unique way. We experience the tree not from the "superior" point of view - observing it on our own horizontal plane - but from beneath it, rooted in the earth and gazing heavenward.

7. Pablo Picasso - Guernica (1937), oil on canvas, 11 ft., 6 in. by 25 ft., 8 in. Picasso painted Guernica in response to the bombing of the ancient Basque city during the Spanish Civil War. The painting has become an internationally recognizable image of pacifism that testifies to the power of art to serve as an active forum for social critique and as an instrument for change.

8. Jackson Pollock - Alchemy (1947), oil, aluminum paint, and string on canvas. Pollock brought physicality and intuition to the forefront of artistic consciousness. By putting the canvas on the floor and physically moving around it to fling paint onto it, Pollock created paintings significant both as objects in and of themselves and as evidence of the process of their creation.

9. Andy Warhol - Marilyn Diptych (1962), acrylic and silkscreen on canvas. The first work in his celebrity series exemplifies Warhol's (and our) fascination with pop culture, the creation and consequences of fame, and the influence of mass media. His deadpan approach to the world is still common in contemporary life and art.

10. Sol LeWitt - Wall Drawing No. 652 (1990), color ink washes superimposed. LeWitt's view of the idea as the machine that makes the art took the relationship between concept and art object to an unprecedented extreme. Drawn directly on a gallery wall, LeWitt's wall drawings are significant for their intrinsic impermanence and for their ability to be constantly renewed and re-created in different locations.

I accepted this assignment thinking it would be fun, and have found instead that it has been a difficult and frustrating task. So I begin with a disclaimer: For every object I have selected, others easily could have been chosen with equally compelling arguments.

1. Chartres Cathedral (1145-1220), Chartres, France. For me, Chartres epitomizes spiritual power and the unity of the arts. Every aspect of its architecture, sculpture, and stained glass reflects the devotion of its makers, each individual working to create a harmonious design that expresses profound faith.

2. Michelangelo - Sistine Ceiling (1508-1512), frescoes, Sistine Chapel in Rome. Leonardo, Raphael, or Michelangelo? Painting or sculpture? I have changed my list countless times, and have selected the Sistine Ceiling to stand for the many accomplishments of the Italian Renaissance. A painting of compelling beauty, it celebrates both the spiritual and physical worlds.

3. Rogier van der Weyden - The Deposition from the Cross (1435), oil on wood. This is one of the most beautiful and moving paintings I have ever seen. Artists of the northern Renaissance are admired for their ability to render even the smallest details of the physical world. In addition to that technical prowess, van der Weyden expressed deep psychological insight in his "Deposition," communicating great sorrow through pose, gesture, and expression.

4. Rembrandt van Rijn - The Artist in his Studio (1627-28), oil on panel. I have selected one image to represent Rembrandt's self portraits. In it, I see the mystery of the artist's relationship with his own work - he stands dwarfed by a canvas that only he can see, in a shadowy and obscure space. It also marks a secular, not a religious, experience; such subjects begin their steady increase in popularity during the Baroque period.

5. Louis-Jacques-Mand Daguerre - portrait photographs (1839 to 1840s). The development of photographs by Daguerre and others in 1839 started a revolution in visual culture that continues today. At first regarded as mechanical representations of the physical world, and as a cheap method of creating portraits, photographs are now valued for their artistic qualities.

6. Joseph Mallord William Turner - The Slave Ship: Slavers Throwing Overboard the Dead and Dying, Typhoon Coming On (1840), oil on canvas. Turner devoted himself to landscape painting, which he transformed to convey not only natural effects, but also emotion and perception. In this example, his interpretation of an actual event had political impact, particularly in the United States, where it became a powerful symbol for the abolitionist movement when it entered a Boston collection.

7. douard Manet - Olympia (1863), oil on canvas. I had first thought to include on my list a nude by Titian, whose Venus of Urbino (1538) established a tradition of sensual images of women that was carried forward by many painters. Then I decided on Manet's nude, which shocked Paris by its bold representation of a naked prostitute, unembellished by the trappings of mythology, which by its very realism provoked a discussion of the nature of art.

8. Claude Monet - Impression: Sunrise (1873), oil on canvas. It marks the beginning of Impressionism, an artistic style that has proven to be one of the most long-lasting and popular. For Monet, the artist's perception of the visual world was paramount, and on his canvases design is as important as representation and one sees the transformation of three-dimensional worlds into two-dimensional surfaces.

9. Pablo Picasso - Les Demoiselles d'Avignon (1907), oil on canvas. Picasso and his colleagues believed that an artist need not be confined by a single vantage point, and invented a new method of representation that incorporated different points of view into a single image. This move toward abstraction had an enormous impact on 20th-century art.

10. Jackson Pollock - Autumn Rhythm: Number 30, 1950, oil on canvas. The center of the art world moved to the US after World War II. Pollock's abstract, emotional celebration of the unconscious, free from any confinement or convention, was among its most influential products, and like Manet's "Olympia," provoked new discussions about the nature of art.

It has been a very humbling experience trying to define the 10 greatest works of art of the past millennium. A scholar of the 18th century, I have not included a single work from that era (although Jean-Antoine Watteau's "Sign of Gersaint in Berlin" is perhaps my single favorite painting).

I have favored instead the most ambitious and successful of the vast painted decorations, architectural jewels, and sculptural schemes through the Baroque era, and masterpieces that show the depth, breadth, conceptual, and emotional power of the greatest masters of the art of painting from that point on. These are works that have shaped our civilization, and without them, we would be immeasurably spiritually bereft.

1. Chartres Cathedral - Northwest Tower, (1140); the Rose Windows (1217-25). The only existing Gothic cathedral fully glazed with a unified program of stained glass to create a saturated, electric atmosphere. Both the tower and the stained glass make the spirit soar and serve as a landmark of architectural ensembles.

2. Jan and Hubert Van Eyck - Ghent Altarpiece (1423-32), oil on panel. These brothers introduced the art of oil painting at a level that it would seldom achieve. Their technical accomplishment is surpassed only by the complexity and reverence of their conception in this extraordinary altarpiece, moving in its vastness as well as its details.

3. Masaccio - Brancacci Chapel (1427), frescoes. The founder of Italian Renaissance painting not only introduced linear perspective but brought his figures a convincing sense of weight and volume, and a compellingly powerful, emotional tenor.

4. Michelangelo - Sistine Chapel (1508-12 and 1535), frescoes, Rome. Although Michelangelo considered himself a sculptor, his painted decoration of the Sistine Chapel ceiling and altar wall is simply the most comprehensive and spiritually charged ensemble of all time. Its force is so great that its impact can be read in the work of artists who have experienced it.

5. Raphael - Vatican Stanze (1508-20), frescoes. The papal apartments that Raphael decorated dominated the mature years of his brief life. The wide-ranging subjects of these elegant works include some of the most beautifully painted figures and the most inspirational concepts of civilization.

6. Gianlorenzo Bernini - The Ecstasy of St. Theresa (1645-52), marble statue, life size, Cornaro Chapel, Rome. This piece not only reveals the overwhelming emotive power of sculpture, but does so in a carefully conceived situation that takes advantage of the architectural environment. Wrapped in swirling draperies, her passionate gaze directed to heaven, Bernini's saint epitomizes the age of the Baroque, and is among the first to break traditional boundaries of media and meaning.

7. Diego Velzquez - Las Menias (1656), oil on canvas. Called by Neapolitan artist Luca Giordano the "theology of painting," this enigmatic and sublimely crafted canvas is notable for its fresh, persuasive immediacy and the seemingly disparate challenge of its mysterious psychological and political interconnections. It is a single large canvas that invites yet defies interpretation by its viewers.

8. Rembrandt van Rijn - The Return of the Prodigal Son (1665), oil on canvas. No Top 10 list would be complete without this giant of the Dutch school, whose humanity is expressed in Rembrandt's equally wondrous paintings, prints, and drawings. Like the late work of Titian, it is particularly in his last great paintings, especially of biblical subjects, that his narrative insight and tremendous stature as an artist is revealed.

9. Georges Pierre Seurat - A Sunday Afternoon on the Island of La Grande Jatte (1884-86), oil on canvas. Painting in France in the 19th century reached a height and subsequent popularity that has rarely been equaled. Few artists brought as much genius, scientific thought, theoretical insight, innovative technique, and conceptual ambition to a canvas as did Seurat in this complex masterwork.

10. Pablo Picasso - Guernica (1937), oil on canvas. Certainly the most talented, versatile, and productive artist of the past century, Picasso stretched his art in form and content when he created this immense and powerful diatribe against war that also eerily foretold horrors to come. Produced in an intense and volatile period, it represents the culmination of his art up to that time and speaks for modernism in general.

My first reaction to making a list of the 10 most influential works of the past 1,000 years was to exempt myself completely and simply say "no." In the end, I could not resist.

Are the criteria aesthetic or are influential works of art simply a product of dominant cultures? Is influence about later imitation or the number of people who seek to see the work of art today?

I tried to select objects from a broad range of cultures and media.

1. Chartres Cathedral - the Rose Windows (1217-1225), stained glass, Chartres, France. As part of one of the most complete medieval buildings, the Rose Windows at Chartres transform light into stunning colors and depict the teachings of the Christian faith.

2. Huang Kung-wang - Dwell- ing in the Fu-ch'un Mountains (1347-1350), handscroll, ink on paper. Huang Kung-wang was one of several great masters of the late Yan period, and this magnum opus is one of the most influential works of the long history of Chinese landscape painting.

3. Michelangelo - Sistine Ceiling (1508-1512), frescoes. This work is a tour de force of painting, illusion, and design. It is also one of the most copied (and parodied) works of art.

4. Albrecht Drer - Melencolia I (1514), engraving. As one of Drer's master engravings, Melencolia I is both a stunning display of technical ability and a complex meditation on philosophy and theology.

5. Matthias Grnewald - Isenheim Altarpiece (1510-1515), oil on panel. Perhaps more than any other work of art, the "Isenheim Altarpiece" was the work I had the most difficult time including. While the altarpiece has inspired many artists, including Jaspar Johns, Grnewald enjoyed limited fame until the 20th century. I included this work because it inspired me to become a curator.

6. The Koranic inscriptions on Taj Mahal (completed in 1647), glazed tiles, Agra, India. In the Islamic world, calligraphy has long been the preeminent art form. Many of these texts begin with an invocation of the name of God and represent a particularly long, rich tradition.

7. Benin ancestral Altarpiece of Oba Akenzua I, Brass (18th century), Berlin, Museum fr Vlkerkunde. The art of Benin has been recognized as being technically and intellectually sophisticated and extraordinarily beautiful. This brass altar depicts the Oba, a Benin king, and was part of an ancestral altar.

8. Vincent van Gogh - The Church at Auvers (1890), oil on canvas. The vibrant colors, the humility of the subject, and the inspired handling of paint led me to select this work. Van Gogh radically represented painting as a dynamic and modern form of expression.

9. Dorothea Lange - Migrant Mother, Nipomo, California (1936), gelatin silver print. This photograph of a woman and her three children captures the spirit of humanity and motherhood while recognizing the harsh reality of poverty. There is also embedded in this selection the acknowledgement of the influence of American society, women artists, and photography on 20th-century culture.

10. Various artists - AIDS Memorial Quilt (mid-1980s), various media. I couldn't think of a more appropriate work that captures the democratic ideals of the late 20th century. With more than 41,000 panels, listing more than 80,000 names, the AIDS Memorial Quilt covers more than 17 football fields and is a monument to the common person expressing heartfelt emotions.